Abstract 223: Antibody intracellular activated drug conjugate (AiADC) as novel ADC technology

Antibody drug conjugate (ADC) consisting of antibody and modifier (potent cytotoxic drug with chemical linker) is expected to selectively eliminate cancer cells expressing corresponding cell-surface antigen. More than 60 ADCs are in clinical trials and about 75 percent of its modifiers are based on three series (auristatin, maytansine, and pyrrolobenzodiazepine). Whereas some ADCs show promising clinical benefits, several ADCs may not have shown maximum value of ADC due to their narrow therapeutic windows. The function of modifiers impacts on total characteristics of ADC such as the efficacy, tolerability, and pharmacokinetics (PK). Therefore, further exploration of new types of modifier for ADC technology platform is needed. We designed hydrophilic modifiers which can be activated only inside of target cells. The ADC consisting of certain IgG1 monoclonal antibodies and this modifier (DSP-ADC) showed selective and potent cytotoxicity to target cells with IC50s at picomolar range. The DSP-ADC with the average drug-to-antibody ratio (DAR) of 7-8 was stable in blood circulation and showed favorable PK profiles in mice. Additionally, administration of the DSP-ADC led to dose-dependent suppression of cancer cell proliferation in mice xenograft models and achieved complete remissions at 3 mg/kg without body weight reduction. The toxicity studies of DSP-ADC in rats showed no effect on hematologic parameters up to 100 mg/kg. These modifiers are applicable to various monoclonal antibodies. Taken together, our modifiers can be fundamental component for ADC technology. We present here the novel ADC technology named as antibody intracellular activated drug conjugate (AiADC).

Citation Format: Atsushi Suwa, Kazuo Komiya, Kenta Kadotsuji, Shoko Ochiai, Yosuke Takanashi, Eiji Sugaru, Hitoshi Ban. Antibody intracellular activated drug conjugate (AiADC) as novel ADC technology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 223.

Abstract 3595: DSP-0692, a selective SCD inhibitor, enhances the anti-tumor activity of anti-PD1 antibody

SCD (Stearoyl-CoA Desaturase), a key enzyme for lipid metabolism, is overexpressed in various types of cancer and plays an important role in cancer cell proliferation. We have previously shown that the identification and the functional characterization of DSP-0692, a novel and selective SCD inhibitor. SCD expression was induced in tumor cells cultured in sphere conditions, which were resistant to conventional agents within therapeutic concentration. DSP-0692 showed strong growth inhibition when tumor cells were cultured in sphere conditions, but had little impact on cells cultured under adherent conditions. In addition, DSP-0692 decreased the expression of stemness-related genes in tumor cells as well as in tumor tissues. Treatment with DSP-0692 suppressed tumor growth in multiple models both in single agent or in combination with conventional chemotherapies. DSP-0692 also inhibited WNT/beta-catenin signaling pathway through two different mechanisms (inhibition of Wnt3A secretion and nuclear translocation of beta-catenin). DSP-0692 exhibited lower IC50 value to sphere cells carrying mutations related to WNT/beta-catenin signaling pathway than those without these mutations. Blockade of the coinhibitory checkpoint molecule PD-1 has emerged as an effective treatment for many cancers. However, despite successes in the clinical setting, only a limited subpopulation respond to PD-1 blockade. We hypothesized that the deregulated lipid metabolism of tumor cells and microenvironment function as a barrier to antitumor immunity, and therefore that normalization of lipid metabolism with DSP-0692 might restore response to immunotherapy. Combination of DSP-0692 with anti-PD-1 antibody in the syngeneic CT-26 colon model, a resistant model to anti-PD-1 antibody, augmented tumor regressions relative to each single agent alone. DSP-0692 induced PD-L1 and PD-L2 expression in CT-26 cells, indicating that it is one of a mechanism of restoration of the effect of anti-PD-1 antibody. Our data suggest that remodeling the lipogenic tumor microenvironment has potential to convert patients resistant to immunotherapy into those who may receive clinical benefit of immunotherapy.

Citation Format: Eiji Sugaru, Yudai Furuta, Yoshikazu Nagagaki, Satoshi Ikeda, Yuichi Fukunaga, Hiroki Umehara, Tsuguteru Otsubo, Manabu Watanabe, Shingo Tojo, Miki Hashizume, Yasushi Matsuki, Hitoshi Ban. DSP-0692, a selective SCD inhibitor, enhances the anti-tumor activity of anti-PD1 antibody [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3595.

Abstract 5480: Colorectal cancer cell lines harboring mutation in Wnt/β-catenin pathway shows enhanced sensitivity to the stearoyl-CoA desaturase (SCD) inhibitor, DSP-0692

Colorectal cancer (CRC) is one of the most frequent malignant diseases worldwide. Recent studies suggest that a small subpopulation of cells known as cancer stem cells (CSCs) may promote the high metastasis and relapse associated with CRC. It has been reported that Wnt/β-catenin signaling is aberrantly activated in a variety of cancer including colorectal cancer, and plays a critical role in CSC maintenance.

Here it is shown that a novel SCD inhibitor, DSP-0692, may inhibited Wnt/β-catenin signaling pathway through two different mechanisms in CRC. The effect of SCD inhibition on Wnt3A secretion, in which process post-translational fatty acylation (with palmitoleic acid) is required, was investigated. DSP-0692 led to reduced Wnt3A protein levels secreted in the media in Wnt3A-overexpressing cell line. This result was further confirmed by the TCF/LEF reporter assay in HCT116 incubated with conditional media from L-Wnt3A cells, with or without DSP-0692. DSP-0692 also inhibited exogenous Wnt3A-induced reporter activity. This indicates DSP-0692 may inhibit the β-catenin/Tcf transactivation by additional mechanism in addition to inhibiting Wnt secretion. To clarify this additional mechanism, the effect of DSP-0692 on nuclear translocation of β-catenin was investigated. SCD inhibition led to a decrease of β-catenin amounts within the nucleus. Currently, how SCD inhibition affects nuclear translocation of β-catenin is being investigated. It was confirmed that DSP-0692 exhibited lower IC50 value to sphere cells carrying mutations related to Wnt/β-catenin signaling pathway than those without these mutations. Next, the effect of SCD inhibition on Wnt/β-catenin signaling pathway in vivo was investigated. Treatment with DSP-0692 in a SW620 colorectal cancer xenograft model suppressed mRNA expression of the Wnt/β-catenin target genes, as well as CSC marker gene.

Taken together, these results suggest fatty acid desaturation in tumor cells may have an impact on Wnt/β-catenin signaling pathway and involve in CSC maintenance. The approaches targeting SCD could be a new therapeutic strategy for anti-CSC therapy in CRC.

Citation Format: Yudai Furuta, Yuichi Fukunaga, Satoshi Ikeda, Erina Koga, Hiroki Umehara, Tsuguteru Otsubo, Manabu Watanabe, Futoshi Hasegawa, Hitoshi Ban, Eiji Sugaru. Colorectal cancer cell lines harboring mutation in Wnt/β-catenin pathway shows enhanced sensitivity to the stearoyl-CoA desaturase (SCD) inhibitor, DSP-0692 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5480.

Abstract 3069: DSP-0692, a novel and selective stearoyl-CoA desaturase (SCD) inhibitor targeting cancer stem cells

In recent years evidence has accumulated in support of the cancer stem cells (CSCs) model in cancer chemotherapy resistance, highlighting the urgency and necessity of identifying CSC-specific targets for new cancer therapeutics.

SCD, a key enzyme for lipid metabolism, is overexpressed in various types of cancer and plays an important role in cancer cell proliferation. In particular, recent studies have implicated SCD involved also in the maintenance of CSCs.

Here, the identification and the functional characterization of DSP-0692, a novel and selective SCD inhibitor, is reported, using various pharmacological approaches to address the mechanism of SCD inhibition in cancer cells and its efficacy in preclinical tumor models. In these preclinical models, DSP-0692 inhibited human SCD activity with low nanomolar IC50 values. SCD expression was induced in tumor cells cultured in sphere conditions, which were resistant to conventional agents within therapeutic concentration. DSP-0692 showed strong growth inhibition when tumor cells were cultured in sphere conditions, but had little impact on cells cultured under normal two-dimensional conditions. In addition, DSP-0692 inhibited the CSC-related signaling pathway and decreased CSC markers expression in tumor cells as well as in tumor tissues. Treatment of DSP-0692 as single agent suppressed tumor growth in multiple models. Furthermore, this efficacy was enhanced in combination with conventional chemotherapies in those tumor models. Of note, SCD protein expression in tumor tissues was useful as a predictive marker for the susceptibility to DSP-0692 treatment.

Taken together, these data suggest that inhibition of fatty acid desaturation by DSP-0692 could be a new therapeutic strategy in SCD-positive cancer, with potential to overcome resistance to standard chemotherapies.

Citation Format: Eiji Sugaru, Yudai Furuta, Yuichi Fukunaga, Hiroki Umehara, Tsuguteru Otsubo, Manabu Watanabe, Futoshi Hasegawa, Shingo Tojo, Miki Hashizume, Hitoshi Ban. DSP-0692, a novel and selective stearoyl-CoA desaturase (SCD) inhibitor targeting cancer stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3069.

Fiber-based modulated optical reflectance configuration allowing for offset pump and probe beams

A new fiber-based modulated optical reflectance configuration is developed in this work. The technique maintains the fiber-based heating laser (pump) and detection laser (probe) in close proximity at a fixed separation distance in a ceramic ferrule. The pump beam periodically heats the sample inducing thermal waves into the sample. The probe beam measures the temperature response at a known distance from the pump beam over a range of heating modulation frequencies. The thermal diffusivity of the sample may be calculated from the phase response between the input heat flux and the temperature response of a sample having a reflective surface. The unique measurement configuration is ideal for in situ measurements and has many advantages for laboratory-based systems. The design and development of the system are reported along with theoretical justification for the experimental design. The thermal diffusivities of Ge and SiC are measured and found to be within 10% of reported literature values. The diffusivity for SiO₂ is measured with a relative difference of approximately 100% from the literature value when the ferrule is in contact with the sample. An additional measurement was made on the SiO₂ sample with the ferrule not in contact resulting in a difference of less than 2% from the literature value. The difference in the SiO₂ measurement when the ferrule is in contact with the sample is likely due to a parallel heat transfer path through the dual-fiber ferrule assembly.

Regulation of eotaxin-3/CC chemokine ligand 26 expression by T helper type 2 cytokines in human colonic myofibroblasts

Eotaxins induce the trafficking of eosinophils to the sites of inflammation via CC chemokine receptor 3 (CCR3). In this study, we investigated eotaxin-3/CC chemokine ligand 26 (CCL26) expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD), and characterized the molecular mechanisms responsible for eotaxin-3 expression in human colonic myofibroblasts. Eotaxin-3 mRNA and protein expression was evaluated by real time-polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Eotaxin-3 mRNA expression was elevated significantly in the active lesions of ulcerative colitis (UC) patients. Significant elevations were also observed in the active lesions of Crohn's disease (CD) patients, but this was significantly lower than that detected in the active UC lesions. There were no significant increases in the inactive lesions of UC or CD patients. Colonic myofibroblasts were identified as a major source of eotaxin-3 in the colonic mucosa, and interleukin (IL)-4 and IL-13 enhanced eotaxin-3 mRNA and protein expression significantly in these cells. There was a significant positive correlation between mucosal eotaxin-3 and IL-4 mRNA expression in the active lesions of IBD patients. The IL-4- and IL-13-induced eotaxin-3 mRNA expression was regulated by the signal transducer and activator of transcription-6 (STAT-6) and suppressor of cytokine signalling (SOCS)1-mediated pathways. Interferon (IFN)-γ acts as a negative regulator on the IL-4- and IL-13-induced eotaxin-3 expression via STAT-1 activation. Eotaxin-3 expression was elevated specifically in the active lesions of IBD, in particular UC. Eotaxin-3 derived from colonic myofibroblasts may play an important role in the pathophysiology of UC.

Epithelial expression of interleukin-37b in inflammatory bowel disease

Interleukin (IL)-37 is a member of the IL-1 cytokine family. We investigated IL-37b expression in the inflamed mucosa of inflammatory bowel disease (IBD) patients. Furthermore, we analysed IL-37b expression in human colonic epithelial cells. The human colonic epithelial cell line T84 and human colonic subepithelial myofibroblasts (SEMFs) were used. IL-37b expression in the IBD mucosa was evaluated by immunohistochemistry. IL-37b mRNA and protein expression were determined by real time-polymerase chain reaction (PCR) and Western blotting, respectively. IL-37b was not detected in the normal colonic mucosa. In the inflamed mucosa of IBD patients, epithelial IL-37b expression was increased markedly. In ulcerative colitis (UC) and Crohn's disease (CD) patients, IL-37b expression was enhanced in the affected mucosa. In the intestinal epithelial cell line T84, the expression of IL-37b mRNA and protein was enhanced by tumour necrosis factor (TNF)-α. This IL-37b induction by TNF-α was mediated by nuclear factor (NF)-κB and activator protein (AP)-1 activation. Furthermore, IL-37b inhibited TNF-α-induced interferon-γ-inducible protein (IP)-10 expression significantly in human colonic SEMFs. Epithelial IL-37b expression was increased in IBD patients, especially UC patients. IL-37b may be involved in the pathophysiology of IBD as an anti-inflammatory cytokine and an inhibitor of both innate and acquired immune responses.

Neuroradiologic features in X-linked α-thalassemia/mental retardation syndrome

BACKGROUND AND PURPOSE

X-linked α-thalassemia/mental retardation syndrome (Mendelian Inheritance in Man, 301040) is one of the X-linked intellectual disability syndromes caused by mutations of the ATRX gene and characterized by male predominance, central hypotonic facies, severe cognitive dysfunction, hemoglobin H disease (α-thalassemia), genital and skeletal abnormalities, and autistic and peculiar behavior. More than 200 patients in the world, including >70 Japanese patients, have been diagnosed with ATR-X syndrome.

MATERIALS AND METHODS

We reviewed the brain MRI and/or CT findings of 27 Japanese patients with ATR-X with ATRX mutations retrospectively.

RESULTS

The findings were categorized into 5 types: 1) nonspecific brain atrophy (17/27); 2) white matter abnormalities, especially around the trigones (11/27); 3) widespread and scattered white matter abnormalities (1/27); 4) delayed myelination (4/27); and 5) severe and rapidly progressive cortical brain atrophy (1/27).

CONCLUSIONS

This is the first report on a comprehensive study of brain MRI/CT findings of ATR-X syndrome. Our findings suggest that the ATRX protein seems to be involved in normal myelination. The classification will require revisions in the near future, but it will be helpful in establishing the relationship between ATRX mutation and brain development and understanding the ATRX protein function in the brain.

Facile and stabile linkages through tyrosine: bioconjugation strategies with the tyrosine-click reaction

The scope, chemoselectivity, and utility of the click-like tyrosine labeling reaction with 4-phenyl-3H-1,2,4-triazoline-3,5(4H)-diones (PTADs) is reported. To study the utility and chemoselectivity of PTAD derivatives in peptide and protein chemistry, we synthesized PTAD derivatives possessing azide, alkyne, and ketone groups and studied their reactions with amino acid derivatives and peptides of increasing complexity. With proteins we studied the compatibility of the tyrosine click reaction with cysteine and lysine-targeted labeling approaches and demonstrate that chemoselective trifunctionalization of proteins is readily achieved. In particular cases, we noted that PTAD decomposition resulted in formation of a putative isocyanate byproduct that was promiscuous in labeling. This side reaction product, however, was readily scavenged by the addition of a small amount of 2-amino-2-hydroxymethyl-propane-1,3-diol (Tris) to the reaction medium. To study the potential of the tyrosine click reaction to introduce poly(ethylene glycol) chains onto proteins (PEGylation), we demonstrate that this novel reagent provides for the selective PEGylation of chymotrypsinogen, whereas traditional succinimide-based PEGylation targeting lysine residues provided a more diverse range of PEGylated products. Finally, we applied the tyrosine click reaction to create a novel antibody-drug conjugate. For this purpose, we synthesized a PTAD derivative linked to the HIV entry inhibitor aplaviroc. Labeling of the antibody trastuzumab with this reagent provided a labeled antibody conjugate that demonstrated potent HIV-1 neutralization activity demonstrating the potential of this reaction in creating protein conjugates with small molecules. The tyrosine click linkage demonstrated stability to extremes of pH, temperature, and exposure to human blood plasma indicating that this linkage is significantly more robust than maleimide-type linkages that are commonly employed in bioconjugations. These studies support the broad utility of this reaction in the chemoselective modification of small molecules, peptides, and proteins under mild aqueous conditions over a broad pH range using a wide variety of biologically acceptable buffers such as phosphate buffered saline (PBS) and 2-amino-2-hydroxymethyl-propane-1,3-diol (Tris) buffers as well as others and mixed buffered compositions.

Formylbenzene diazonium hexafluorophosphate reagent for tyrosine-selective modification of proteins and the introduction of a bioorthogonal aldehyde

4-Formylbenzene diazonium hexafluorophosphate (FBDP) is a novel bench-stable crystalline diazonium salt that reacts selectively with tyrosine to install a bioorthogonal aldehyde functionality. Model studies with N-acyl-tyrosine methylamide allowed us to identify conditions optimal for tyrosine ligation reactions with small peptides and proteins. FBDP-based conjugation was used for the facile introduction of small molecule tags, poly(ethylene glycol) chains (PEGylation), and functional small molecules onto model proteins and to label the surface of living cells.

Tyrosine bioconjugation through aqueous ene-type reactions: a click-like reaction for tyrosine

A new and versatile class of cyclic diazodicarboxamides that reacts efficiently and selectively with phenols and the phenolic side chain of tyrosine through an ene-like reaction is reported. This mild aqueous tyrosine ligation reaction works over a broad pH range and expands the repertoire of aqueous chemistries available for small molecule, peptide, and protein modification. The tyrosine ligation reactions are shown to be compatible with the labeling of native enzymes and antibodies in a buffered aqueous solution. This reaction provides a novel synthetic approach to bispecific antibodies. We believe this reaction will find broad utility in peptide and protein chemistry and in the chemistry of phenol-containing compounds.

RUNX3 expression correlates with chief cell differentiation in human gastric cancers

RUNX3 is a novel tumor suppressor in gastric carcinogenesis and an important factor for differentiation of chief cells in the normal gastric fundic mucosa. In this study, we confirmed RUNX3 immunolocalization in the fundic gland (bottom part) but minimum in surface mucous cell epithelium (top part) in the isolated gland from fundic mucosa. We also analyzed RUNX3 expression by immunohistochemistry in 102 gastric cancers and made a histological assessment of the expression of differentiation markers to evaluate interrelations. Among them, 45 and 57 cases were judged to be RUNX3 positive and negative, respectively, and 33 and 69 cases were pepsinogen I positive and negative, with no link to histological types. RUNX3 expression was significantly associated with that of pepsinogen I (P<0.001), but not mucins, including MUC5AC and MUC6, or the parietal or intestinal phenotypes. In conclusion, the present study showed, for the first time to our knowledge, a relation between RUNX3 and pepsinogen I expression in human gastric cancers. RUNX3 is strongly associated with chief cell phenotypic expression in human gastric cancers, as well as in normal gastric mucosa, and could be considered to play an important role in maintaining the chief cell phenotype.

Novel 1,4-diarylpiperidine-4-methylureas as anti-hyperlipidemic agents: dual effectors on acyl-CoA:cholesterol O-acyltransferase and low-density lipoprotein receptor expression

A family of 1,4-diarylpiperidine-4-methylureas were designed and synthesized as novel dual effectors on ACAT and LDL receptor expression. We examined SAR of the synthesized compounds focusing on substitution at the three aromatic parts of the starting compound 1 and succeeded in identifying essential substituents for inhibition of ACAT and up-regulation of hepatic LDL receptor expression. Especially, we found that compound 12f, which can easily be prepared, has biological properties comparable to those of SMP-797, a promising ACAT inhibitor. In addition, the in vitro effects of 12f on lipid metabolism were substantially superior to those of a known ACAT inhibitor, Avasimibe.

Synergistic upregulation of inducible nitric oxide synthase and cyclooxygenase-2 in gastric mucosa of Mongolian gerbils by a high-salt diet and Helicobacter pylori infection

AIMS

The intake of salt and salty food is known as a risk factor for gastric cancer. We have previously demonstrated that a high-salt diet dose-dependently enhances Helicobacter pylori (H. pylori)-associated gastritis and stomach carcinogenesis in Mongolian gerbils. In this study, we focused on the influence of excessive salt intake on the expression of inflammatory mediators involved in progression of H. pylori-induced chronic gastritis.

METHODS AND RESULTS

A total of 45 stomach samples from Mongolian gerbils were evaluated by immunohistochemistry. The animals were infected with H. pylori and fed basal (0.32%) or a high-salt (10%) diet, and sacrificed after 40 weeks. Proliferative activity and expression of cyclooxygenase-2 (COX-2) in gastric mucosa were significantly increased in H. pylori-infected gerbils. The additional high-salt diet significantly up-regulated the expression of inducible nitric oxide synthase (iNOS) and COX-2 in H. pylori-infected groups (P<0.01 and P<0.05, respectively), while no significant effects were noted in non-infected animals. There was significant synergistic interaction between H. pylori infection and 10% NaCl diet on the expression of iNOS (P<0.05) and also a tendency for enhanced COX-2 expression (P=0.0599).

CONCLUSIONS

The present results suggest that a high-salt diet works synergistically with H. pylori infection to enhance iNOS and COX-2 expression in the gastric mucosa of Mongolian gerbils, and support the hypothesis that excessive salt intake may be associated with progression of H. pylori-induced gastritis.

Expression and maturation of Sendai virus vector-derived CFTR protein: functional and biochemical evidence using a GFP-CFTR fusion protein

Sendai virus (SeV) vector has been shown to efficiently transduce airway epithelial cells. As a precursor to the potential use of this vector for cystic fibrosis (CF) gene therapy, the correct maturation of the SeV vector-derived CF transmembrane conductance regulator (CFTR) protein was examined using biochemical and functional analyses. We constructed a recombinant SeV vector, based on the fusion (F) gene-deleted non-transmissible SeV vector, carrying the GFP-CFTR gene in which the N terminus of CFTR was fused to green fluorescence protein (GFP). This vector was recovered and propagated to high titers in the packaging cell line. Western blotting using an anti-GFP antibody detected both the fully glycosylated (mature) and the core-glycosylated (immature) proteins, indicating that SeV vector-derived GFP-CFTR was similar to endogenous CFTR. We also confirmed the functional channel activity of GFP-CFTR in an iodide efflux assay. The efficient expression of GFP-CFTR, and its apical surface localization, were observed in both MDCK cells in vitro, and in the nasal epithelium of mice in vivo. We concluded that recombinant SeV vector, a cytoplasmically maintained RNA vector, is able to direct production of a correctly localized, mature form of CFTR, suggesting the value of this vector for studies of CF gene therapy.

Down regulation of gastric and intestinal phenotypic expression in Epstein-Barr virus-associated stomach cancers

AIMS

We have previously demonstrated the importance of gastric and intestinal phenotypic expression for stomach carcinogenesis. In this study, we focused on Epstein-Barr virus (EBV)-associated stomach cancers, with special attention to Cdx2.

METHODS AND RESULTS

We evaluated the expression of gastric and intestinal phenotypic markers by immunohistochemistry in 35 EBV-positive [EBV (+)] and 75 EBV-negative [EBV (-)] stomach cancers in Colombia. The lesions were divided phenotypically into gastric (G), gastric-and-intestinal mixed (GI), intestinal (I), and null (N) phenotypes. In the EBV (+) cases, the lesions were divided phenotypically into 9 G (25.7%), 1 GI (2.9%), 3 I (8.6%), and 22 N (62.9%) types. Similarly, the EBV (-) lesions were also classified phenotypically as 15 G (20.0%), 19 GI (25.3%), 24 I (32.0%), and 17 N (22.7%) types. The proportion of N type EBV (+) lesions was higher than for their EBV (-) counterparts (P<0.0001). The expression of Cdx2 and MUC2 was also found to be significantly lower in EBV (+) than in EBV (-) stomach cancers (P=0.0001; P<0.0001). Cdx2 expression in the intestinal metaplastic glands present in non-neoplastic mucosa surrounding EBV (+) lesions was also significantly lower than in EBV (-) tumors (P=0.016) despite no evidence of EBV infection.

CONCLUSIONS

EBV (+) stomach cancers are characterized by low expression of intestinal phenotype markers, including Cdx2, and only occasional gastric phenotypic expression.

Sendai virus-mediated CFTR gene transfer to the airway epithelium

The potential for gene therapy to be an effective treatment for cystic fibrosis has been hampered by the limited gene transfer efficiency of current vectors. We have shown that recombinant Sendai virus (SeV) is highly efficient in mediating gene transfer to differentiated airway epithelial cells, because of its capacity to overcome the intra- and extracellular barriers known to limit gene delivery. Here, we have identified a novel method to allow the cystic fibrosis transmembrane conductance regulator (CFTR) cDNA sequence to be inserted within SeV (SeV-CFTR). Following in vitro transduction with SeV-CFTR, a chloride-selective current was observed using whole-cell and single-channel patch-clamp techniques. SeV-CFTR administration to the nasal epithelium of cystic fibrosis (CF) mice (Cftr(G551D) and Cftr(tm1Unc)TgN(FABPCFTR)#Jaw mice) led to partial correction of the CF chloride transport defect. In addition, when compared to a SeV control vector, a higher degree of inflammation and epithelial damage was found in the nasal epithelium of mice treated with SeV-CFTR. Second-generation transmission-incompetent F-deleted SeV-CFTR led to similar correction of the CF chloride transport defect in vivo as first-generation transmission-competent vectors. Further modifications to the vector or the host may make it easier to translate these studies into clinical trials of cystic fibrosis.

Loss of MUC2 expression correlates with progression along the adenoma-carcinoma sequence pathway as well as de novo carcinogenesis in the colon

AIMS

We have previously demonstrated links between clinicopathological findings and phenotypes using several gastric and intestinal phenotypic markers in stomach and pancreatic cancers. However, the clinicopathological significance of the phenotype and Cdx2 expression has hitherto remained unclear in colorectal carcinogenesis.

METHODS AND RESULTS

We examined the correlation between gastric and intestinal phenotypic expression in 91 primary early carcinomas of the colon. MUC2 expression demonstrated a significant decrease from tubular/tubulovillous adenomas with moderate atypia, through intramucosal carcinomas, to cancers with submucosal invasion (P<0.0001). Intramucosal de novo carcinomas (flat type carcinomas without adenomatous components) exhibited a greater decrease of MUC2 than intramucosal lesions with adenomatous components. Expression of MUC5AC also decreased significantly with progression according to the tubular/tubulovillous adenoma-carcinoma sequence, carcinomas with villous adenomatous components having a higher level compared with their tubular adenomatous counterparts, suggesting differences in the pathway of malignant transformation. Cdx2 nuclear expression was maintained in all of the adenomas and early carcinomas examined.

CONCLUSIONS

Our data suggest that the reduction of MUC2 expression may be associated with the occurrence and progression of colorectal carcinomas in both adenoma-carcinoma sequence pathway and de novo carcinogenesis. Tumor-suppressive effects of Cdx2 may be preserved during early stages of colorectal carcinogenesis.

Gastric and intestinal phenotypic correlation between exocrine and endocrine components in human stomach tumors

We have previously suggested that an origin of a stomach cancer is from a progenitor cell specializing toward exocrine cell (Exo-cell) lineages. To clarify whether our hypothesis is correct or not, we analyzed the expression of Exo-cell and endocrine cell (End-cell) markers in a series of lesions for comparison. We evaluated chromogranin A (CgA) expression in 37 early and 73 advanced stomach cancers, in 30 stomach adenomas, in 8 carcinoid tumors, and in 4 endocrine cell carcinomas (ECCs) with assessment of gastric and/or intestinal (G/I) phenotypes in both Exo-cell and End-cell by immunohistochemistry. CgA expression was observed in 10.8% of the early and 16.4% of the advanced stomach cancers, respectively. The End-cell G/I phenotypes were in line with the Exo-cell counterparts in the CgA-positive stomach cancerous areas, and there was strong association between Cdx2 expression and the intestinal End-cell markers. All of the adenoma cases had the intestinal Exo-cell phenotypic expression, with the positive link between Exo-cell and End-cell G/I phenotypes. All stomach carcinoids had CgA expression but no expression of Exo-cell markers. In conclusion, most stomach cancers might develop from a progenitor cell specializing towards Exo-cell lineages, but some cases possessed both Exo-cell and End-cell markers with maturely differentiated phenotypes. In such cases, Exo-cell and End-cell phenotypes were found to correlate strongly, suggesting the possibility of histogenesis from "cancer stem cells".

Synthesis and biological activity of novel 4-phenyl-1,8-naphthyridin-2(1H)-on-3-yl ureas: Potent acyl-CoA:cholesterol acyltransferase inhibitor with improved aqueous solubility

4-Aryl-1,8-naphthyridin-2(1H)-on-3-yl urea derivatives with hydrophilic groups were synthesized in order to improve aqueous solubility and pharmacokinetic property. SMP-797 possessing (4-aminophenyl)ureido and 3-(hydroxypropoxyphenyl) moieties showed potent ACAT inhibitory activity and excellent oral efficacy.

Laser cooling transitions in atomic erbium

We discuss laser cooling opportunities in atomic erbium, identifying five J ? J + 1 transitions from the 4f126s2 3H6 ground state that are accessible to common visible and near-infrared continuous-wave tunable lasers. We present lifetime measurements for the 4f11(4Io 15/2)5d5/26s2 (15/2, 5/2)7o state at 11888 cm-1 and the 4f11(4Io 13/2)5d3/26s2 (13/2, 5/2)7o state at 15847 cm-1, showing values of 20 +/- 4 micros and 5.6 +/- 1.4 micros, respectively. We also present a calculated value of 13 +/- 7 s-1 for the transition rate from the 4f11(4Io 15/2)5d3/26s2 (15/2, 3/2)7 o state at 7697 cm-1 to the ground state, based on scaled Hartree-Fock energy parameters. Laser cooling on these transitions in combination with a strong, fast (5.8 ns) laser cooling transition at 401 nm, suggest new opportunities for narrowband laser cooling of a large-magnetic moment atom, with possible applications in quantum information processing, high-precision atomic clocks, quantum degenerate gases, and deterministic single-atom doping of materials.

Molecular cloning of a novel importin alpha homologue from rice, by which constitutive photomorphogenic 1 (COP1) nuclear localization signal (NLS)-protein is preferentially nuclear imported

Nuclear import of proteins that contain classical nuclear localization signals (NLS) is initiated by importin alpha, a protein that recognizes and binds to the NLS in the cytoplasm. In this paper, we have cloned a cDNA for a novel importin alpha homologue from rice which is in addition to our previously isolated rice importin alpha1a and alpha2, and we have named it rice importin alpha1b. In vitro binding and nuclear import assays using recombinant importin alpha1b protein demonstrate that rice importin alpha1b functions as a component of the NLS-receptor in plant cells. Analysis of the transcript levels for all three rice importin alpha genes revealed that the genes were not only differentially expressed but that they also responded to dark-adaptation in green leaves. Furthermore, we also show that the COP1 protein bears a bipartite-type NLS and its nuclear import is mediated preferentially by the rice importin alpha1b. These data suggest that each of the different rice importin alpha proteins carry distinct groups of nuclear proteins, such that multiple isoforms of importin alpha contribute to the regulation of plant nuclear protein transport.

Portal hypertensive enteropathy in biliary atresia

This paper describes a rare case of biliary atresia (BA) in which massive postoperative bleeding developed due to portal hypertensive enteropathy. A 15-year-old boy had been doing well after Kasai's operation for BA. At around the age of 6 years he developed recurrent episodes of esophageal variceal bleeding and underwent esophageal transection, splenectomy, sclerotherapy, and embolization of the left gastric vein. At the age of 15 years he suddenly developed abdominal pain, hematemesis, and massive tarry stools. His hemoglobin level was 6.3 g/dl. Endoscopy showed several small, polypoid lesions in the jejunum beyond Treitz' ligament. The source of the bleeding was one of these lesions located in the proximal jejunojejunostomy of the Roux-en-Y loop. Because he had repeated episodes of melena, he underwent partial resection of the jejunum under endoscopic guidance. He has since been free of gastrointestinal (GI) bleeding. From this experience, we conclude that the polypoid lesions of an enteropathy may be a cause of massive GI bleeding in the postoperative portal hypertension of BA.

Transumbilical resection and umbilical plasty for patent omphalomesenteric duct

This paper describes a transumbilical resection and umbilical plasty for treatment of a patent omphalomesenteric duct (POMD). In a newborn infant with a POMD, a skin incision was made circumscribing the mucocutaneous junction of the protruded duct. The duct was completely extirpated with a wedge resection of the connection to the intestine and an umbilical plasty was performed. The postoperative appearance was excellent. It appears that transumbilical resection and umbilical plasty may be a satisfactory operation for POMD.

Abdominal wall plasty for a premature infant with congenital diaphragmatic hernia

This paper reports a premature infant with a congenital diaphragmatic hernia (CDH) who underwent an abdominal wall plasty to enlarge the abdominal cavity, one of twin infants born at 32 weeks weighing 1,255 g. After stabilization, the herniated viscera were reduced from the pleural cavity and the abdominal wall muscle and skin layers were replaced by a Gore-tex patch without closure of the diaphragmatic defect. Respiratory and circulatory conditions were stable during the perioperative period. Postoperatively, a roentogenogram showed expansion of the lung. However, his condition deteriorated 24 h after surgery, triggered by intratracheal suction, and he died on the 4th day of life despite the use of high-frequency oscillation, catecholamines, and vasodilators. Postmortem examination showed severely hypoplastic lungs. Abdominal wall plasty may be a less invasive initial procedure, however, further studies, such as comparison with the standard method or conservative management, are needed using a large clinical group or animal models to justify the usefulness of this procedure.